Such processes for the hydrogenation of esters are in general known from a great variety of literature and using a large number of diverging types of catalysts. However, all these catalytic hydrogenation processes have in common that they operate inseparable from the application of high pressures and high temperatures and moreover require the use of pure hydrogen as reducing agent.
It will be appreciated that such relative extreme reaction conditions put heavier demands to construction and materials for the equipment to be used for these processes, which means a significant operational cost increasing factor.
Therefore, there is still a need for an improved process of the hydrogenation of esters into alcohols, which may be carried out under economically attractive operational conditions and which should not inevitably require pure hydrogen gas but should be carried out in the presence of hydrogen containing gases such as synthesis gas (H.sub.2 :CO=2:1) or other commercially available hydrogen containing gas mixtures optionally containing inert gas components, such as helium or nitrogen.
As a result of extensive research and experimentation such an improved process aimed at, was surprisingly found.